Answer:
36.36% probability that she gave birth to quadruplets
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcoes.
Desired outcomes:
Giving births to quadruplets.
She has 4 sets of quadruplets.
So 
Total outcomes:
At least 3 children(triplets).
7 sets of triplets and 4 sets of quadruplets.
So 
Probability:

36.36% probability that she gave birth to quadruplets
Speed = Distance/Time. Let speed be V, distance D and time T
a)Given: D₁ =45km, V₁=x km/h
V₁=D₁/T
V₁=45/T OR T= 45/V₁
b) Given : D₂ =48 km and V₂ = V₁ + 4 km/h
V₂ = 48/T, but V₂ = V₁+4, then:
V₁+4 = 48/T OR T=48/(V₁+4). Since Time is same, then we can write:
45/V₁ =48/(V₁+4), solve for V₁:
45V₁ + 180 = 48V₁
3V₁ =180 and V₁ = x = 60 km/h
Step-by-step explanation:
First we need to find out what they all 3 equal, with multiplication.
5×5=25
10×5=50
20×5=100
In each of these problems, the answer is multiplying itself by 2 in order to get to the next answer. So this is how they are related
Answer:
9/10
Step-by-step explanation:
There are 20 and 2 green 20-2 is 18 so 18/20 simplified is also 9/10